[2.0][DDC-254] Improved MappingException thrown on missing required configuration of Many-Many mapping

lib/Doctrine/ORM/Mapping/ManyToManyMapping.php

@@ -83,11 +83,17 @@ class ManyToManyMapping extends AssociationMapping
             }
             // owning side MUST specify joinColumns
             if ( ! isset($mapping['joinTable']['joinColumns'])) {
-                throw MappingException::invalidMapping($this->_sourceFieldName);
+                throw MappingException::missingRequiredOption(
+                    $this->sourceFieldName, 'joinColumns', 
+                    'Did you think of case sensitivity / plural s?'
+                );
             }
             // owning side MUST specify inverseJoinColumns
             if ( ! isset($mapping['joinTable']['inverseJoinColumns'])) {
-                throw MappingException::invalidMapping($this->_sourceFieldName);
+                throw MappingException::missingRequiredOption(
+                    $this->sourceFieldName, 'inverseJoinColumns', 
+                    'Did you think of case sensitivity / plural s?'
+                );
             }
             
             foreach ($mapping['joinTable']['joinColumns'] as &$joinColumn) {

lib/Doctrine/ORM/Mapping/MappingException.php

@@ -74,6 +74,26 @@ class MappingException extends \Doctrine\Common\DoctrineException
         return new self("The mapping of field '$fieldName' requires an the 'joinTable' attribute.");
     }
     
+    /**
+     * Called if a required option was not found but is required
+     * 
+     * @param string $field which field cannot be processed?
+     * @param string $expectedOption which option is required
+     * @param string $hint  Can optionally be used to supply a tip for common mistakes, 
+     *                      e.g. "Did you think of the plural s?"
+     * @return MappingException 
+     */
+    static function missingRequiredOption($field, $expectedOption, $hint = '') 
+    {
+        $message = "The mapping of field '{$field}' is invalid: The option '{$expectedOption}' is required.";
+
+        if ( ! empty($hint)) {
+            $message .= ' (Hint: ' . $hint . ')';
+        }
+
+        return new self($message);
+    }
+    
     /**
      * Generic exception for invalid mappings.
      *